No benefit of convalescent plasma in COVID-19 patients, study finds

June 5, 2020

Convalescent plasma therapy did not help 52 seriously ill COVID-19 patients recover in the first known randomized study of its kind, although it was stopped early because of low enrollment. The study, published in JAMA, involved coronavirus patients with severe illness (respiratory distress and/or low oxygen levels) or life-threatening disease (shock, organ failure, or the need for mechanical ventilation) in seven medical centers in Wuhan, China, from February 14 to April 1, with final follow-up on April 28.

The trial was stopped early because, owing to containment of the Wuhan outbreak, researchers were able to recruit only 103 of 200 patients needed to generate a clinically meaningful result. One patient withdrew from the study, and one in the control group received convalescent plasma, a protocol violation, because of a life-threatening infection.

Convalescent plasma therapy, which dates back to the early 20th century, involves the transfusion of blood plasma collected from patients recovered from infection to improve immune response in the recipient. Although evidence supporting its use in COVID-19 patients is scarce, the U.S. Food and Drug Administration (FDA) recently approved its emergency use in patients who have severe or life-threatening coronavirus infection.

The authors noted that most previous studies on convalescent plasma lacked standardization and procedure control in donor selection and the type or level of antibodies in the convalescent plasma. The researchers called for further studies on optimal patient selection and timing of convalescent plasma therapy in COVID-19 patients.

In a commentary in the same journal, Arturo Casadevall, MD, PhD, of the Johns Hopkins Bloomberg School of Public Health in Baltimore and colleagues said that while convalescent plasma didn't lead to significant improvements in clinical status or death rate, the study generated "potentially hopeful signals," adding that convalescent plasma may be useful in combination with antiviral drugs.

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